Regular cannabis use that starts in adolescence strips away IQ, a NIDA-supported study suggests. Participants who initiated weekly cannabis use before age 18 dropped IQ points in proportion to how long they persisted in using the drug. Persistent cannabis users’ cognitive difficulties were evident to friends and family and measurable on a battery of tests.

New research demonstrated that, in rhesus monkeys, ongoing cocaine exposure weakens two brain functions that people require for successful behavioral change: cognitive flexibility and memory. But the study determined that these changes may not be permanent.

Researchers found that 1 in 8 high school seniors had used a prescription opioid nonmedically, and 70 percent of these teens had compounded the attendant risk by co-ingesting an opioid with one or more other drugs. Nonmedical opioid use was significantly more prevalent among whites than among African Americans or Hispanics.

When the goal is to avoid using alcohol and illicit substances after being released from jail, it’s who one’s friends are that counts most. Self-control is important because it helps a person have the right kind of friends.

A new vaccine hindered the often-abused prescription opioids oxycodone and hydrocodone from entering the brain and suppressed one of the drugs’ signature central nervous system effects. The findings warrant continued development of the vaccine as a potential aid in the treatment of oxycodone and hydrocodone abuse and dependence.

Men benefit more than women from nicotine replacement therapy for smoking cessation because nicotine affects a key neuroreceptor differently in the two sexes, a NIDA-sponsored study suggests. The findings highlight the need for alternative therapies for women smokers, and point to the female hormone progesterone as a potential therapeutic target.